Pumping units

ABSTRACT

Sound generated by a submerged motor-pump unit and transmitted through the liquid in which the unit is submerged is attenuated by shielding means comprising a first box-like member having a downwardly facing opening and a second box-like member having an upwardly facing opening and overlapping the first box-like member. The box-like members are made from sheet metal coated with foam rubber or other sound-absorbing material.

United States Patent 1191 Related US. Application Data Montelius 1 1Mar. 27,1973

54 PUMPING UNITS 3,087,578 4/1963 Reed et al ..1s1/33 K 3,102,246 111970 Honey et al. [75] Inventor g Montehus Djurslwlm 3,294,025 12 1966Niemeyer et al. ..3 10/87 we 1,610,774 12/1926 Hanson ..417 312 73 A e:Akt'ebl t Imo-Industr', 1

[ 1 6 zf fi FOREIGN PATENTS OR APPLICATIONS g 448,08l 4/1948 Canada..l8l/33.4 I 971,765 10 1964 Great Britain .....181 33.4

[21] Appl. No.: 175,357 1,114,626 12 1955 France ..181/33.4

Primary ExaminerCarlton R. Croyle Assistant Examiner-Richard E. GluckAttorneyBusser, Smith and Harding [57] ABSTRACT Sound generated by asubmerged motor-pump unit and transmitted through the liquid in whichthe .unit is upwardly facing opening and overlapping the first boxlikemember. The box-like members are made from sheet metal coated with foamrubber or other soundabsorbing material.

1 Claim, 1 Drawing Figure PATENTEDHARZTIHB 3,728,027

INVENTOR TORSTEN MONTELIUS ATTORNEYS PUMPING UNITS This application is acontinuation of Ser. No. 883,559 filed Dec. 9, 1969, now abandoned.

The present invention relates to an improvement in pumping unitscomprising a pump and a motor which are immersed below the liquid levelin a liquid tank. The object of the invention is to provide an improveddampening of noise in such a unit.

It is known in hydraulic installations to dispose the main feeding pumpof the installation together with its driving motor immersed in ahydraulic fluid tank. This has several advantages, inter alia that themotor and pump construction can be considerably simplified. However,difficult problems of preventing noise are encountered. Some of them canbe solved by suspending the pump and motor assembly in vibrationdampening members arranged in a suitable manner. However, vibrationsfrom the pump may still be transmitted through the fluid to the tankwalls and result in disturbing noise.

According to the present invention, an improved absorption of noise isachieved by providing within the tank a shield enclosing the pump andmotor and consisting wholly or partly of sound absorbing material. Thisshield is arranged so that free circulation of the fluid between thespaces within and outside .of the shield is possible.

An embodiment of the invention is illustrated on the accompanyingdrawing.

Referring to the drawing, the numeral 1 designates an oil tank having acover 2. A pump 3 together with a driving motor 4 is arranged so thatboth the pump and the motor are below the normal liquid level 5. In theembodiment illustrated, the pump and the motor are suspended by cables 6in vibration dampers 7 of rubber. A valve means 8 is positioned on thecover 2 and communicates with the pump outlet through a conduit 9. Areturn conduit 10 extends from the valve to the interior of the tank.Further, conduits (notshown) extend from the valve for connection toother parts of the hydraulic installation, which are to be operated byhydraulic fluid.

According to this invention, there is provided a shield 11 enclosing thepump 3 and motor 4, in the embodiment shown, constructed as an open boxhaving the open side facing downwards. The box may be made from sheetmetal coated with foam' rubber or other sound absorbing material. It isdisposed by means of attachment members (not shown) so that its bottomedge is spaced a short distance above the tank bottom, whereby oil fromthe space outside of the box can enter the space within the box. Theboxhas suitable openings through which the above-mentioned conduits andcables extend.

The shape of the shield is unimportant, as long as it essentiallyencloses the pump and motor assembly, preferably both upwardly andlaterally.

In order to further improve the dampening of noise, it is possible toprovide a similar box 12 enclosing the pump motor assembly from below,i.e. having its open side at the top. This box is made with somewhatlarger dimensions than shield 11 and disposed so that it partly enclosesbox 11 with-a sufficient space therebetween to permit 'free circulationof liquid alternatively, box 11 could be made with dimensions such thatit partly encloses box 12.

I claim:

1. A pumping unit comprising a tank for containing a I liquid to bepumped, a pump 'and motor assembly.

disposed in the tank below the normal liquid level therein, andshieldingmeans essentially enclosing the.

pump and motor assembly comprising first and second box-like members,each made at least 'in part from sound-absorbing material, and eachhaving one open

1. A pumping unit comprising a tank for containing a liquid to bepumped, a pump and motor assembly disposed in the tank below the normalliquid level therein, and shielding means essentially enclosing the pumpand motor assembly comprising first and second box-like members, eachmade at least in part from sound-absorbing material, and each having oneopen end, said members having their open ends facing in oppositedirections and being so arranged that one at least partially enclosesthe other with a space between their walls to allow circulation ofliquid between the spaces within and outside of the shielding means.